Management Accounts vs The Books

how do businesses in practice deal with the fact that management accounts may need to have things showing in different periods to the books/ Vat records?

eg invoice from supplier A relates to event on 28 Feb but invoice is dated 3 March?

Is it common practice to download the books into excel and then move things around? Surely most small businesses then have problems with the management accounts not actually reconciling to the books or balancing in terms of double entry?

Any light you can shed on this process would be much appreciated. My boss who is not an accountant currently gets our assistant to retype each Purchase Order and Invoice into an excel Tracker. Everything is then individually reentered into a cloud accounts package similar to basic sage.

Do any versions of Quickbooks deal with this problem automatically without entering everything twice?